Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752442Ab3HUPlF (ORCPT ); Wed, 21 Aug 2013 11:41:05 -0400 Received: from mail-ee0-f52.google.com ([74.125.83.52]:45111 "EHLO mail-ee0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752415Ab3HUPlC (ORCPT ); Wed, 21 Aug 2013 11:41:02 -0400 Date: Wed, 21 Aug 2013 18:39:57 +0300 From: Sergey Senozhatsky To: Frederic Weisbecker Cc: Stanislaw Gruszka , Ingo Molnar , Peter Zijlstra , "Paul E. McKenney" , Borislav Petkov , linux-kernel@vger.kernel.org Subject: Re: [sched next] overflowed cpu time for kernel threads in /proc/PID/stat Message-ID: <20130821153957.GA2969@swordfish.minsk.epam.com> References: <20130820111426.GA27828@swordfish.datadirectnet.com> <20130820151509.GA17441@somewhere> <20130820153549.GB2315@swordfish.minsk.epam.com> <20130820154257.GD17441@somewhere> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130820154257.GD17441@somewhere> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1115 Lines: 35 On (08/20/13 17:42), Frederic Weisbecker wrote: > On Tue, Aug 20, 2013 at 06:35:50PM +0300, Sergey Senozhatsky wrote: > > On (08/20/13 17:15), Frederic Weisbecker wrote: > > > On Tue, Aug 20, 2013 at 02:14:26PM +0300, Sergey Senozhatsky wrote: > > > Hello, > > > > > > Please upload your config. > > > > > > I'm adding Stanislaw in Cc in case it relates to cputime scaling. > > > > > > > please find attached. > > > > -ss > > > # > > # CPU/Task time and stats accounting > > # > > CONFIG_VIRT_CPU_ACCOUNTING=y > > CONFIG_VIRT_CPU_ACCOUNTING_GEN=y > > So it happens with full dynticks cputime accounting. > How reproducable is this? Does it always happen? > Does it happen with CONFIG_TICK_CPU_ACCOUNTING as well? (you'll > need to deactivate full dynticks.) in cputime_adjust() `stime' is greater than `rtime', so `utime = rtime - stime' sets wrong value. -ss -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/